Dry powder inhaler

ABSTRACT

A drug powder inhaler has a cover plate pivotably attached to a lid on an inhaler housing. A lever is pivotably attached to the cover plate. A blister pack disk is rotatably mounted on the housing under the cover plate. A powder duct in the housing extends from a staging chamber underneath one end of the lever to an aerosolizing chamber. An actuator in the housing is pressed to shear open a blister on the blister pack disk and thereby deliver the drug dose contents of the blister into the staging chamber. A switch senses pressure in the mouthpiece and switches on a motor spinning an impeller within the aerosolizing chamber, when inhalation is detected.

BACKGROUND OF THE INVENTION

[0001] This application is a continuation of U.S. patent applicationSer. No. 09/351,895, filed Jul. 13, 1999, and now pending, which is acontinuation-in-part of application Ser. No. 08/428,960, filed Apr. 24,1995 and now U.S. Pat. No. 5,622,166, and incorporated herein byreference.

FIELD OF THE INVENTION

[0002] The field of the invention is inhalers. More specifically, theinvention relates to inhalers for delivering drugs in a solid finelydivided dry powder or fluid form.

[0003] Inhalers are used to deliver drugs into a patient's lungs.Typically, an inhaler contains or provides a mixture of drugs and air orpropellants. The mixture is delivered via the patient inhaling from amouthpiece on the inhaler, for treatment of various conditions, forexample, bronchial asthma. However, delivery of drugs via inhalation canbe used for many other treatments, including those unrelated to lungcondition.

[0004] One well known inhaler, the Diskhaler, described in U.S. witheach successive dose. However, while the device described in U.S. Pat.No. 4,627,432 has met with varying degrees of success, disadvantagesremain in indexing or advancing a blister disk within an inhaler, withopening the blisters to access the drug contents, with reliablyproviding intended dosages, and in other areas.

[0005] Accordingly, it is an object of the invention to provide animproved inhaler.

SUMMARY OF THE INVENTION

[0006] To these ends, the present inhaler preferably includes a coverplate pivotably attached to a lid on an inhaler housing. A blister packdisk is rotatably mounted on the housing under the cover plate, and ismovable in a single forward direction. An actuator in the housing ismost desirably aligned with a lever on the cover plate. The patientpushes the actuator which shears open a blister on the disk and thencauses the lever to crush the blister, to deliver the drug powdercontents of the blister into a duct within the housing, for subsequentinhalation by the patient.

[0007] Other and further objects will appear hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In the drawings, wherein similar reference characters denotesimilar elements throughout the several views:

[0009]FIG. 1 is perspective view of the present inhaler with themouthpiece covered by the cover assembly;

[0010]FIG. 2 is a perspective view thereof with the mouthpieceuncovered;

[0011]FIG. 3 is a plan view of the inhaler as shown in FIG. 1;

[0012]FIG. 4 is a plan view of the inhaler as shown in FIG. 2;

[0013]FIG. 5 is an exploded perspective view of the inhaler of FIGS. 1and 2;

[0014]FIG. 6 is an plan view of the inhaler of FIGS. 1 and 2 with thelid open;

[0015]FIG. 7 is a partial section view taken along line 7-7 of FIG. 6;

[0016]FIG. 8 is an enlarged top and front perspective view of the coverassembly on the inhalers of FIGS. 1 and 2;

[0017]FIG. 9 is a bottom and rear perspective view of the cover assemblyof FIG. 8;

[0018]FIG. 10 is an enlarged view of features shown in FIG. 9;

[0019]FIG. 11 is a partial section view taken along line 11-11 of FIG.5;

[0020]FIG. 12 is similar view showing positions of various componentsduring use of the device;

[0021]FIG. 13 is a partial section view taken along line 13-13 of FIG.3;

[0022]FIG. 14 is a partial section view taken along line 14-14 of FIG.4;

[0023]FIGS. 15, 16 and 17 are partial section view fragmentsillustrating movement of components within the device;

[0024]FIG. 18 is a section view taken along line 18-18 of FIG. 5;

[0025]FIG. 19 is a similar view thereof with various components omittedfor drawing clarity, and showing positions of components during use;

[0026]FIG. 20 is an exploded perspective view of a blister disk for usewith the inhaler shown in FIGS. 1 and 2;

[0027]FIG. 21 is a partial plan view thereof; and

[0028]FIG. 22 is a section view taken along line 22-22 of FIG. 21.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Turning now in detail to the drawings, as shown in FIGS. 1-4, adry powder inhaler includes a housing 32 having a lid 38 attached to thehousing with a hinge 36. The lid 38 is preferably a transparentmaterial, e.g., clear plastic. A removable mouthpiece 34 is provided onone side of the housing 32. A sliding cover assembly 40 may be pivotedon the lid 38 from a closed position covering the mouthpiece 34, asshown in FIGS. 1 and 3, to an opened position exposing the mouthpiece34, as shown in FIGS. 2 and 4. As best shown in FIGS. 3 and 4 (lookingdown through the transparent lid 38), a disk 42 having a plurality ofradially spaced apart blisters 44 is generally centered on top of thehousing 32 on a center post 140 extending upwardly from the housing 32.A lid stop 46 on the housing 32 limits sliding movement of the coverassembly 40 in the opened position.

[0030] Turning momentarily to FIGS. 8 and 9, the sliding cover assembly40 includes an enclosure 48 having a front curved wall 54, a side wall56, a top wall 58 and a bottom wall 60. A rim 62 extends upwardly andradially inwardly on the top wall 58.

[0031] Referring now to FIG. 9, a glide block 64 and an outside retainer66 extend downwardly and inwardly on the underside of the top wall 58. Agenerally flat cover plate 50 is preferably integrally formed with theenclosure 48, with the cover plate 50 and enclosure comprising the coverassembly 40. An inside retainer 68 on the cover plate 50 extendsradially outwardly. A lever 74 is pivotably supported on a lever pin 76held in place by lever blocks 72 on the underside of the cover plate 50.The lever 74 can pivot through a lever opening 78 in the cover plate 50,as best shown in FIG. 8. A ramp 80 and a guide wall 82 projectdownwardly from the cover plate 50, adjacent to the lever 74, as shownin FIG. 9. The entire cover assembly 40, which includes the enclosure 48and cover plate 50 is pivotably attached to the lid 38, with the lidpost 52 extending through a center hub 84 on the cover plate 50.Clearance holes 70 through the cover plate 50 on either side of thelever opening 78 allow the cover plate to sit on top of the blisterdisk, as shown in FIG. 18, without excessive vertical interference.

[0032] Referring to FIGS. 8, 9 and 10, a spring arm 86 having adownwardly projecting end tab 88 is attached to or integral with thecover plate 50. As shown in FIG. 13, the spring arm 86 includes an armwedge 96 at its free end, alongside the tab 88. As shown in FIG. 10, anarm lifter 102 extends downwardly from the lid 38. An outer slot 94through the cover plate 50 overlies the spring arm 86. An inner slot 92adjoining the outer slot 94 through the cover plate 50 providesclearance for the arm lifter 102, and allows the cover assembly 40 torotate (preferably about 90°). The arm lifter 102 includes an internalramp, and is dimensioned to engage the arm wedge 96, and lift the arm 86up towards the lid 38, as the arm wedge 96 moves into full engagementwith the lifter 102.

[0033] Turning now to FIG. 5, the housing 32 includes a mixing chamber120, and a staging chamber 124 connected to the mixing chamber 120 via aduct 122. Referring now also to FIGS. 6 and 7, an inlet duct 126 extendsfrom one side of the housing 32 to the staging chamber 124 via a ductrecess 130. A crescent barrier 128 around the top of the staging chamber124 creates an indirect air flow path from outside of the housing,through the inlet duct 126 and into the staging chamber 124.

[0034] In a first embodiment of the present invention, referring onceagain to FIG. 5, a pressure port or opening 132 in the housing 32alongside the mixing chamber 120 connects to a pressure switch 170 via atube 172. The pressure port aligns with a mouthpiece port 135 leadinginto the central opening of the mouthpiece. This provides a continuousduct from the mouthpiece opening to the pressure switch. The mouthpiece34 or an alternative embodiment mouthpiece 136 is secured to the housing32 with a hook 134. The mouthpiece is removable by twisting or rotatingthe mouthpiece, to disengage the hook 134, and then by pulling it off.Rachet posts 142 having angled top surfaces project slightly above theflat top surface 138 of the housing 32. An actuation button 146 has apost 148 extending entirely through a post opening 144 in the housing32.

[0035] Referring momentarily to FIG. 18, a detent 145 on the housingengages and holds the post 148 in the up position (driving the lever tocrush a blister), until the disk is advanced to the next blister. At thefront of the housing, behind the mixing chamber 120, is an inwardlyprojecting housing inner rim 150, and an outwardly projecting housingouter rim 152. The outer rim 152 is engaged by the outside retainer 66,and the inner rim is engaged by the inside retainer 68, as the coverassembly 40 is moved between opened and closed positions. Theinteraction of the inner rim 150 and inside retainer 68 and outer rim152 and outside retainer 66, holds the cover assembly and lid down ontop of the housing 32.

[0036] Referring still to FIG. 5, a bottom cover 158 attached to thehousing 32 has a button recess 164 around the actuation button 146, sothat the actuation button 146 does not project beyond the bottom surfaceof the cover 158. An impeller 162 within the mixing chamber 120 issupported on the shaft of an electric motor 160 behind the mixingchamber 120 in the housing 32. The motor 160 is wired to batteries 168and the pressure switch 170. A battery indicator LED 174 and a statusindicator LED 176 are positioned in the housing 32, above the pressureswitch 170.

[0037] Turning now to FIGS. 20-22, the disk 42 includes a blister foilring 190, preferably a metal or aluminum foil having generally conicalblisters formed in it. The blister foil ring 190 and a foil seal ring192 are adhered or bonded onto a carrier disk 194. As shown in FIG. 21,the carrier disk 194 has tabs 196 suspended within tab slots 198 bybridges 200. Each blister 44 on the blister foil ring 190 is alignedover a tab 196. The bridges 200 hold the tabs 196 in position, but allowthe tab to pivot about the bridges, with nominal torque. As shown inFIG. 22, powdered drug 202 is sealed within the blisters 44. The carrierdisk 194 is preferably plastic. The tab supports 200 are small enough tosupport the tabs 196, but also to allow the tab to pivot under force ofthe post of the actuation button.

[0038] In use, a disk 42 is first loaded into the inhaler 30 by slidingthe cover assembly 40 from the closed position shown in FIG. 1 to theopen position shown in FIG. 2. In this position, the lid 38 and coverassembly 40 are still held down on top of the housing 32 by theinteraction of the outside retainer 66 and inside retainer 68 on thehousing outer rim 152 and inner rim 150. The side wall 56 of theenclosure 48 is lifted slightly away from the housing 32, to a allow itto pass over the lid stop 46. As this occurs, the retainers 66 and 68move off of and release from the inner and outer rims 150 and 152. Thecover assembly 40 and lid 38 are then pivoted upwardly about the hinge36, to open up the inhaler 30, as shown in FIG. 6, for placement orreplacement of a disk 42.

[0039] A disk 42 is placed over the center post 140 over the housing topsurface 138 with the blisters 44 on top. The lid 38 and cover assembly40 are pivoted back about the hinge 36, from the position shown in FIG.6, to the position shown in FIG. 2. The inhaler 30 is then ready foruse.

[0040] The rachet posts 142 on the housing top surface 138 projectslightly into the open ends 203 of the tab slots 198. The disk 42 isaccordingly oriented so that a blister 44 will be aligned over thestaging chamber 124. The rachet posts 142 also prevent the disk 42 frommoving in reverse (i.e., clockwise in FIG. 6).

[0041] With the lid 38 closed, but with the cover assembly 40 opened (asshown in FIG. 2), the inner end of the lever 74 is aligned over the topof the post 148. The outer end of the lever 74 is aligned over the topof a blister 44, and over the staging chamber 124.

[0042] With the inhaler 30 preferably held upright, the actuation button146 is pushed up. As shown in FIGS. 11, 12 and 19, the upward movementof the post 148 on the actuation button 146 first pivots the tab 196 onthe blister 44 over the staging chamber 124. The tab pivots on thebridges 200. As this occurs, the foil seal ring 192 sealing the blister44 on the bottom shears away opening the blister and allowing thepowdered drug 202 to fall into the staging chamber 124.

[0043] As upward movement of the post 148 continues, the post pivots thelever 74 causing the outer end of the lever to crush the blister 44down, to release any residual powder into the staging chamber 124.

[0044] With one dose of the powdered drug now delivered from a sealedblister 44 into the staging chamber 124, the patient places themouthpiece 34 into the mouth and inhales. The inhalation draws air fromoutside of the housing through the inlet duct 126, around and under thecrescent barrier 128 and into the staging chamber 124. Air and powdereddrug 202 move through the duct 122 and into the mixing chamber 120. Atthe same time, upon inhalation, the reduced air pressure at themouthpiece 136 is detected by the pressure switch 170 via the tube 172extending to the pressure port 132. The switch 170 turns on the motor160, spinning the impeller 162 within the mixing chamber 120. The airand drug is mixed in the mixing chamber 120, as further described inU.S. Pat. Nos. 5,327,883, and 5,577,497, incorporated herein byreference. As the impeller is already spinning at high speed when thedrug enters the mixing chamber, the air/drug mixing and deagglomerationare enhanced.

[0045] The patient inhales on the mouthpiece drawing in the air/drugmixture from the mixing chamber 120 via holes 125 in the rear wall ofthe mouthpiece 34 (which rear wall also forms the front wall of themixing chamber 120).

[0046] To prepare for delivery of the next dose, the cover assembly 40is moved from the position shown in FIG. 2, to the position shown inFIG. 1, to cover the mouthpiece 34. As this closing movement of thecover assembly 40 occurs, the arm wedge 96 on the spring arm 86 isreleased from the lifter 102. This allows the spring arm 86 to flexdownwardly with the tab 88 engaging into the opened end 202 of a tabslot 198, approximately at position A as shown in FIGS. 3 and 6. Withthe continued closing motion of the cover assembly 40 to the positionshown in FIG. 3, the tab 88 on the spring arm 86 advances the disk 42 tothe next blister 44 (moving the disk 42 counter-clockwise in FIG. 3).For a disk having 16 blisters, the advancing movement, from engagementof the tab 88 to the disk 42, until the end of movement, is about 22°.As the disk 42 is advanced by the spring arm 86 on the closing coverassembly 40, the disk 42 rides up and over the angled top surfaces ofthe rachet posts 142 and then settles back down onto the housing surface138 with the rachet posts 142 engaged into the next set of opened ends203 of the tab slots 198. In this manner, the next blister 44 on thedisk 42 is positioned for delivery and inhalation, as described above.When the cover assembly 40 is reopened, to the position shown in FIG. 4,the disk 42 does not move, as the spring arm 86 is lifted up and outfrom engagement with the disk by the interaction of the lifter 102 onthe lid 38 and the arm wedge 96 on the spring arm 86. Through thisrepeated motion of opening and closing the cover assembly 40, eachblister 44 on the disk 42 can be sequentially accessed, until all of theblisters are used.

[0047] As the cover assembly 40 is closed, the ramp 80 on the coverplate 50 rides over the top of the post 148, the push it down, resettingthe actuation button 146 for the next dose, as shown in FIGS. 15-17.Simultaneously, the guide wall 82, which ramps upwardly from the lever74, pushes down on the pivoted tab 196 from the blister delivered. Thetab 196 is accordingly pushed back down into the plane of the disk 42,so that the disk can be advanced without interference. The rachet posts142 prevent the disk 42 from moving in reverse (clockwise in FIG. 3) atanytime.

[0048] Accordingly, a novel inhaler is described and shown with variousadvantages over the prior art design. The above-described inhaler maycontain various changes and modifications, including varioussubstitutions and equivalents, without departing from the spirit andscope of the present invention.

We claim:
 1. An inhaler comprising: a housing; a staging chamber in thehousing, with the staging chamber having an open top, to allow a dose ofa dry powder pharmaceutical to move via gravity into the staging chamberfrom a dose carrier above the staging chamber, and with the stagingchamber having a substantially closed bottom end to allow the stagingchamber to temporarily hold the dose of dry powder; a mixing chamber inthe housing spaced apart from the staging chamber; and an enclosedcontinuous duct extending from the staging chamber to the mixingchamber.
 2. The inhaler of claim 1 further comprising an inlet extendinginto the housing to the staging chamber.
 3. The inhaler of claim 1further comprising a barrier between the staging chamber and the inlet.4. The inhaler of claim 1 further comprising means for opening the dosecarrier aligned above the staging chamber.
 5. The inhaler of claim 1wherein the enclosed duct extends substantially horizontally in thehousing.
 6. The inhaler of claim 1 wherein the duct and the mixingchamber have round cross sections, and the diameter of mixing chamber isgreater than the diameter of the duct.
 7. An inhaler comprising: ahousing; an air flow path extending through the housing and comprising:an inlet extending into the housing; a staging chamber within thehousing with the inlet joining into the staging chamber; a mixingchamber within the housing; a duct in the housing having a first endconnecting into the staging chamber and having a second end connectinginto the mixing chamber.
 8. The inhaler of claim 7 further comprising amouthpiece forming a wall of the mixing chamber.
 9. The inhaler of claim7 with the mixing chamber having a circumferential wall between flatfirst and second walls, and wherein the duct connects into the mixingchamber through the first flat wall.
 10. The inhaler of claim 7 whereinthe staging chamber has an open top for receiving a dose of power viagravity.
 11. The inhaler of claim 9 wherein the circumferential wall hasa diameter greater than the diameter of the duct.
 12. The inhaler ofclaim 7 wherein the staging chamber has a closed off bottom surface andan open top end.
 13. The inhaler of claim 12 wherein the duct connectsinto the staging chamber adjacent to the closed off bottom surface. 14.The inhaler of claim 7 further including a mouthpiece connecting to themixing chamber and wherein the duct provides the only connection betweenthe staging chamber and the mixing chamber, such that all air enteringinto the mixing chamber via the duct, upon inhalation on the mouthpieceby a user of the inhaler, comes from the staging chamber.
 15. Theinhaler of claim 7 wherein the duct has a round cross section.
 16. Theinhaler of claim 15 wherein the duct has a length greater than itsdiameter.
 17. The inhaler of claim 7 with the housing having a flat topsurface and the duct extends in a direction parallel to the flat topsurface.
 18. The inhaler of claim 7 wherein the duct is longer than theinlet.